#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netdb.h>

void error_handling(char *message) {
    fputs(message, stderr);
    fputc('\n', stderr);
    exit(1);
}

int main(char argc, char **argv) {
    struct hostent *host;
    if (argc != 2) {
        printf("Usage : %s <addr>\n", argv[0]);
        exit(1);
    }
    host = gethostbyname(argv[1]);
    if (!host)
        error_handling("get host error");
    
    printf("official name %s\n", host->h_name);
    for (int i = 0; host->h_aliases[i]; i++)
        printf("Aliases %d : %s \n", i + 1, host->h_addr_list[i]);
    printf("Address type %s \n", host->h_addrtype == AF_INET ? "AF_INET":"AF_INET6");
    for (int i = 0; host->h_addr_list[i]; i++) 
        printf("IP addr %d : %s\n", i + 1, inet_ntoa(*(struct in_addr *)host->h_addr_list[i]));
}
